Thrombolysis In Retinal Vessels With Ultrasound

Abstract

Systems and methods are described providing for the use of ultrasound energy to effect the dislodging of one or more blood clots inside blood vessels. Such clots can include those inside retinal vessels, especially in patients with central retinal vein occlusion. Embodiments of the present disclosure may be used for any retinal arterial or venous occlusion. In exemplary embodiments, a small probe can be inserted into the eye of a patient and placed over the retinal vessels. Acoustic streaming created by the probe can be directed to an area or region including targeted blood vessels, resulting in increased flow in one or more retinal veins and facilitating or effecting mechanical dislodging of one or more blood clots in the targets blood vessels. Exemplary embodiments can utilize ultrasonic energy produced at a frequency of approximately 44 MHz to 46 MHz with pulse repetition frequencies of approximately 100 Hz to 100 kHz.

1 . An ultrasonic needle transducer system comprising:
 an ultrasonic needle transducer for producing an output of ultrasound energy, the transducer including a piezoelectric material and being configured and arranged for intraocular insertion;   a control unit connected to the ultrasound transducer and configured and arranged to control the production of ultrasound energy from the transducer.   
   
   
       2 . The system of  claim 1 , wherein the ultrasound transducer further comprise a light source. 
   
   
       3 . The system of  claim 1 , wherein the ultrasound transducer comprises a laser probe. 
   
   
       4 . The system of  claim 1 , wherein the ultrasound transducer with comprises a flat, angled, or beveled tip. 
   
   
       5 . The system of  claim 1 , wherein the piezoelectric material comprises PMN-PT. 
   
   
       6 . The system of  claim 1 , wherein the ultrasound transducer includes a cylindrical housing. 
   
   
       7 . The system of  claim 4 , wherein the cylindrical housing comprises steel. 
   
   
       8 . The system of  claim 7 , wherein the steel comprises stainless steel. 
   
   
       9 . The system of  claim 6 , further comprising a tube of electrically insulating material disposed within the cylindrical housing. 
   
   
       10 . The system of  claim 9 , wherein the flexible tube comprises polyimide. 
   
   
       11 . The system of claim  35  wherein the PMN-PT comprises PMN-33% PT. 
   
   
       12 . The system of  claim 1 , wherein the control unit comprises timing circuitry and a power amplifier for supplying the transducer with a signal for driving the transducer at a ultrasonic frequency. 
   
   
       13 . The system of  claim 1 , wherein the control unit is configured and arranged to control the intensity of the ultrasonic output of the transducer. 
   
   
       14 . The system of  claim 1 , wherein the control unit is configured and arranged to control the pulse repetition frequency (PRF) of the output of the transducer. 
   
   
       15 . The system of  claim 1 , wherein the transducer is configured and arranged to detect an ultrasonic reflection signal and further comprising Doppler processing circuitry configured and arranged to receive the ultrasonic reflection signal and produce corresponding velocity information. 
   
   
       16 . The system of  claim 15 , further comprising a spectrogram configured and arranged to display and capture velocity information received from the Doppler processing circuitry. 
   
   
       17 . The system of  claim 1 , wherein the transducer and controller are configured and arranged to produce ultrasonic energy at a frequency of about 1 MHz to about 50 MHz. 
   
   
       18 . The system of  claim 1 , wherein the controller is configured and arranged to produce a pulse repetition frequency of about 100 Hz to about 100 kHz. 
   
   
       19 . The system of  claim 1 , wherein the controller is configured ad arranged to produce a pulse cycle count from 1 to 255. 
   
   
       20 . A method of performing thrombolysis in a blood vessel, the method comprising:
 inserting an ultrasound transducer into a patient;   placing the transducer over or adjacent to blood vessels of the patient;   producing ultrasonic energy from the transducer;   directing the ultrasonic energy to the retinal vessels; and   effecting thrombolysis in one or more blood vessels.   
   
   
       21 . The method of  claim 20 , wherein directing the ultrasonic energy to the retinal vessels comprises producing acoustic streaming or ultrasound shockwaves. 
   
   
       22 . The method of  claim 21 , wherein producing acoustic streaming comprises producing acoustic streaming or ultrasound shockwaves in a targeted retinal blood vessel containing one or more blood clots. 
   
   
       23 . The method of  claim 20 , further comprising detecting an ultrasonic reflection signal and producing corresponding velocity information from the reflection signal. 
   
   
       24 . The method of  claim 20 , wherein producing ultrasonic energy from the transducer comprises producing ultrasonic energy at a frequency of about 1 MHz to about 50 MHz. 
   
   
       25 . The method of  claim 24 , wherein the ultrasonic energy is produced at a frequency of about 44 MHz to about 24 MHz. 
   
   
       26 . The method of  claim 20 , wherein producing ultrasonic energy from the transducer comprises producing a pulse repetition frequency of about 100 Hz to about 100 kHz. 
   
   
       27 . The method of  claim 20 , wherein producing ultrasonic energy from the transducer comprises producing a pulse cycle count from 1 to 255. 
   
   
       28 . The method of  claim 20 , wherein producing ultrasonic energy from the transducer comprises using a piezoelectric needle probe. 
   
   
       29 . The method of  claim 27 , wherein the needle probe comprises PMN-PT. 
   
   
       30 . The method of  claim 20 , wherein inserting the probe into a patient comprises inserting the probe into an eye of the patient. 
   
   
       31 . The method of  claim 20 , wherein placing the transducer over or adjacent to blood vessels of the patient comprises placing the transducer over or adjacent to retinal vessels of the eye or the optic nerve of the patient.